TXU0104: Design Review

Apurva Agre

Part Number: TXU0104
Other Parts Discussed in Thread: TXU0102

Tool/software:

Hello,

We are planning to use the TXU0104PWR in one of our designs. In this design, the input signals MCU_RST_1V8 and MCU_BOOT_1V8 come from the EC25 microcontroller, which has VOH(min) = 1.35V and VOL(max) = 0.45V. Are these voltage levels acceptable for the TXU0104PWR? Could you please review the attached design and let us know if any changes are needed?

Regards
Apurva Agre

1 month ago

0 Michael Ikwuyum 1 month ago

TI__Mastermind 29775 points

Hi Apurva,

The voltage levels are acceptable and schematics looks good, thanks.

Best Regards,

Michael.

0 Clemens Ladisch 1 month ago

Guru 272400 points

Unused input (A3, A4) must not be left floating.

The V_OH(min) is specified for a certain load current. If there is no pull-down resistor or another load, then the actual load current is zero, and the actual V_OH will be 1.8 V. (In general, connecting CMOS inputs and outputs at the same supply voltage always works and does not require comparing voltage ranges.)

0 Apurva Agre 1 month ago in reply to Clemens Ladisch

Prodigy 100 points

Hello Clemens and Michael,
Thanks for response, so the unused pins should be connected to ground.
In our case VCCA is less than VCCB, is it ok? as in the datasheet I do not see any case when VCCA is not equal to VCCB.

+1 Clemens Ladisch 1 month ago in reply to Apurva Agre

Guru 272400 points

You are connecting the outputs of the 1.8 V MCU to the 1.8 V inputs of the level shifter; this is the same and is OK.

For two signals, the TXU0102 would be a simpler choice.

+1 Michael Ikwuyum 1 month ago in reply to Apurva Agre

TI__Mastermind 29775 points

Hi Apurva,

In addition to Clemens' feedback, please help note TXU devices have internal pull-downs and unused pins can be left floating or connected to GND, thanks.

Best Regards,

Michael.

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TXU0104: Design Review